1. Field of the Invention
The present invention relates to a cutting tool, and, more specifically, to a rotary milling cutting tool particularly adapted for cutting an expanded synthetic resinous material such as a Styrofoam plastic.
2. State of the Prior Art
As set forth in U.S. Pat. No. 5,429,460 issued in the name of the present inventor, expanded plastic forms are typically hand cut to shape from cast starting blocks of material. A larger starting block of the material is conveniently fabricated by laminating together two or more cast blocks. When a typical hand tool, saw or a grinding-type cutter is used to profile cut the block or to dress the outside surface, a relatively rough finish surface results, primarily from the cellular or bead nature of the foam or expanded plastic material which cause beads or cells to pull away from the stock block being machined.
The aforementioned U.S. Pat. No. 5,429,460 sets forth the details of a machine for cutting expanded plastic work pieces. The basic parameters of the cutting tool are also disclosed which include a rotary cutter having a plurality of generally radially extending openings which fluidly communicate with the axial bore through the cutter. A source of vacuum in the machine entrains cutting material debris in air for evacuating through the radial openings and axial bore.
U.S. Pat. No. 5,626,444, also issued in the name of the present inventor, discloses a rotary cutting tool including features described in the aforementioned patent. This patent also defines the tool as having intersecting cutters disposed at the intersections of right-hand and left-hand flutes in the tool shank which creates components of force in opposite directions along the axis of the tool. In addition, successive axial rows of cutters will overlap diametrical cutting paths alternating between cutters on the leading edges of a right-hand and left-hand helical flute. These oscillating cutting forces in combination with instant evacuation of the material being removed from the workpiece produces a clean, fine, finished work surface.
However, it would still be desirable to provide an improved rotary cutting tool of the kind disclosed in the aforementioned patent which has greater cutting efficiency, particularly at the lead end of the tool in the bottom of a cut hole or bore. It would also be desirable to provide a rotary cutting tool of the aforementioned kind which can be easily inserted into a hole without excess cut material buildup on the tool or below the leading edge of the tool.